U.S. patent application number 16/697331 was filed with the patent office on 2020-05-28 for liquid absorbing device, control method for liquid absorbing device, and liquid absorbing material.
This patent application is currently assigned to SEIKO EPSON CORPORATION. The applicant listed for this patent is SEIKO EPSON CORPORATION. Invention is credited to Yoichi MIYASAKA.
Application Number | 20200164653 16/697331 |
Document ID | / |
Family ID | 70770477 |
Filed Date | 2020-05-28 |
United States Patent
Application |
20200164653 |
Kind Code |
A1 |
MIYASAKA; Yoichi |
May 28, 2020 |
LIQUID ABSORBING DEVICE, CONTROL METHOD FOR LIQUID ABSORBING
DEVICE, AND LIQUID ABSORBING MATERIAL
Abstract
A liquid absorbing device includes: a liquid absorber containing
fibers and an anionic absorbent resin designed to absorb a liquid;
a container having a feed port to which the liquid is supplied, a
storage section that is connected with the feed port and that
stores the liquid absorber, an inflow section configured such that
part of the liquid flows into when the liquid is supplied to the
storage section, and a communicating portion that connects the
storage section with the inflow section; and a detection unit that
is provided in the inflow section and that is configured to detect
a surface of the liquid in the inflow section.
Inventors: |
MIYASAKA; Yoichi; (Suwa-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEIKO EPSON CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
SEIKO EPSON CORPORATION
Tokyo
JP
|
Family ID: |
70770477 |
Appl. No.: |
16/697331 |
Filed: |
November 27, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41J 2/16508 20130101;
B41J 2/1721 20130101; B41J 2/16523 20130101 |
International
Class: |
B41J 2/17 20060101
B41J002/17 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2018 |
JP |
2018-222222 |
Claims
1. A liquid absorbing device comprising: a liquid absorber
including fibers and an absorbent resin designed to absorb a
liquid; a container having a feed port to which the liquid is
supplied, a storage section that is connected with the feed port
and that stores the liquid absorber, an inflow section configured
such that part of the liquid flows into when the liquid is supplied
to the storage section, and a communicating portion that connects
the storage section with the inflow section; and a detection unit
that is provided in the inflow section and that is configured to
detect a surface of the liquid in the inflow section.
2. The liquid absorbing device according to claim 1, wherein the
communicating portion is provided between a lower portion in the
vertical direction of the storage section and a lower portion in
the vertical direction of the inflow section.
3. The liquid absorbing device according to claim 1, wherein the
detection unit includes an electrode for electrically detecting the
surface of the liquid.
4. The liquid absorbing device according to claim 1, wherein the
detection unit includes a window for optically detecting the
surface of the liquid.
5. The liquid absorbing device according to claim 1, wherein: the
liquid absorber is a small piece aggregate composed of a plurality
of small pieces which are each formed by impregnating a fiber
substrate containing the fibers with an anionic absorbent resin;
and each of the small pieces is in a plate shape having two
principal surfaces mutually in a front and rear relationship.
6. The liquid absorbing device according to claim 5, wherein the
small pieces satisfy the following three requirements A, B, and C:
A: when the liquid is a low-concentration liquid having an
electrolyte concentration of less than 1% by mass at 25.degree. C.,
a ratio of a mass [g] of the low-concentration liquid absorbed into
the anionic absorbent resin to a mass [g] of the anionic absorbent
resin is 20 or more and 600 or less, B: when the liquid is a
high-concentration liquid having an electrolyte concentration of 1%
by mass or more at 25.degree. C., a ratio of a mass [g] of the
high-concentration liquid absorbed into the anionic absorbent resin
to the mass [g] of the anionic absorbent resin is 10 or more and
less than 20, and C: each of the small pieces satisfies
relationships of a.sup.1/2/b>5 and 0.01.ltoreq.b.ltoreq.10.00
wherein a is an area [mm.sup.2] of one of the two principal
surfaces and b is a thickness [mm] in a normal direction to the
principal surfaces.
7. The liquid absorbing device according to claim 5, wherein a
longest inner diameter on a cross-section of the communicating
portion is 0.1 mm or more and less than a length of a shortest side
on the principal surfaces of the small pieces.
8. The liquid absorbing device according to claim 1, wherein the
fibers are cellulose fibers.
9. The liquid absorbing device according to claim 1, wherein a
proportion of a volume of the inflow section to a volume of the
storage section is 0.01% or more and 10.0% or less.
10. A control method for the liquid absorbing device according to
claim 1, comprising: acquiring data about frequency or time when a
height of the surface of the liquid detected by the detection unit
exceeds a reference value; and determining a type of the liquid
based on the data.
11. A liquid absorbing material being a small piece aggregate
composed of a plurality of small pieces each formed by impregnating
a fiber substrate containing fibers with an anionic absorbent
resin, wherein the small piece aggregate exhibits different
absorption characteristics depending on an electrolyte
concentration of a liquid to be absorbed.
12. The liquid absorbing material according to claim 11, wherein
each of the small pieces has at least a first principal surface and
a second principal surface facing a side opposite to the first
principal surface and is in a plate shape having the principal
surfaces exposed outside.
Description
[0001] The present application is based on, and claims priority
from JP Application Serial Number 2018-222222, filed Nov. 28, 2018,
the disclosure of which is hereby incorporated by reference herein
in its entirety.
BACKGROUND
1. Technical Field
[0002] The present disclosure relates to a liquid absorbing device,
a control method for the liquid absorbing device, and a liquid
absorbing material.
2. Related Art
[0003] In an ink jet printer, waste ink is typically generated, for
example, during head cleaning that is performed to prevent
deterioration in printing quality due to clogging with ink or
during ink filling after an exchange of ink cartridges. For this
reason, an ink jet printer includes a liquid absorber for absorbing
waste ink to prevent unintended attachment of such waste ink to
internal mechanisms or the like of the printer.
[0004] For example, JP-A-2014-040045 discloses a waste ink storage
structure including: a storage space for storing waste ink; a waste
ink introduction section for introducing waste ink into the storage
space; a ventilation hole for connecting the storage space to the
outside; and two layers of an ink absorbing material that are
filled in the storage space and absorb waste ink through
permeation. As the ink absorbing material, a liquid absorber
including cellulose fibers, a heat-fusible substance, and a
fireproofing substance is disclosed. Moreover, it is also disclosed
that the ink absorbing material is used particularly for absorbing
pigment ink, in which pigment particles are dispersed.
[0005] Meanwhile, either pigment ink or dye ink is assigned to a
given ink jet printer as a usable type of ink. For example, the ink
absorbing material described in JP-A-2014-040045 is primarily used
for absorbing pigment ink. When dye ink is mistakenly used, there
is thus a risk of impairing output image quality, causing clogging
of a head, or the like. Accordingly, there is a need for a means
that can detect what type of liquid is used for liquids having
different electrolyte concentrations, such as pigment ink and dye
ink.
SUMMARY
[0006] The present disclosure was accomplished to meet at least
part of the above-mentioned need and can be realized as
follows.
[0007] The liquid absorbing device of the present disclosure is
characterized by including a liquid absorber containing fibers and
an absorbent resin designed to absorb a liquid; a container having
a feed port to which the liquid is supplied, a storage section that
is connected with the feed port and that stores the liquid
absorber, an inflow section configured such that part of the liquid
flows into when the liquid is supplied to the storage section, and
a communicating portion that connects the storage section with the
inflow section; and a detection unit that is provided in the inflow
section and that is configured to detect a surface of the liquid in
the inflow section.
[0008] A control method for the liquid absorbing device of the
present disclosure is characterized by including acquiring data
about frequency or time when a height of the surface of the liquid
detected by the detection unit exceeds a reference value; and
determining a type of the liquid based on the data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partial vertical cross-sectional view
illustrating a liquid absorbing device according to a first
embodiment.
[0010] FIG. 2 is a partial vertical cross-sectional view
illustrating the liquid absorbing device according to the first
embodiment in use.
[0011] FIG. 3 is a perspective view illustrating small pieces as an
exemplary form of a liquid absorber included in the liquid
absorbing device of FIGS. 1 and 2.
[0012] FIG. 4 is a perspective view illustrating disintegrated
fibers as another exemplary form of the liquid absorber included in
the liquid absorbing device of FIGS. 1 and 2.
[0013] FIG. 5 is a flow chart showing a control method for the
liquid absorbing device according to the first embodiment.
[0014] FIG. 6 is a partial vertical cross-sectional view
illustrating a liquid absorbing device according to a second
embodiment in use.
[0015] FIG. 7 is a conceptual diagram illustrating a liquid
absorbing device according to a third embodiment.
[0016] FIG. 8 is a partial vertical cross-sectional view
illustrating a liquid absorbing device according to a fourth
embodiment in use.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0017] Hereinafter, a liquid absorbing device, a control method for
the liquid absorbing device, and a liquid absorbing material of the
present disclosure will be described in detail based on preferred
embodiments illustrated in the attached drawings.
First Embodiment
[0018] First, a liquid absorbing device according to the first
embodiment will be described. FIG. 1 is a partial vertical
cross-sectional view illustrating the liquid absorbing device
according to the first embodiment. FIG. 2 is a partial vertical
cross-sectional view illustrating the liquid absorbing device
according to the first embodiment in use. FIG. 3 is a perspective
view illustrating small pieces as an exemplary form of a liquid
absorber included in the liquid absorbing device of FIGS. 1 and 2.
FIG. 4 is a perspective view illustrating disintegrated fibers as
another exemplary form of the liquid absorber included in the
liquid absorbing device of FIGS. 1 and 2. In the description
hereinafter, the upper side and lower side in FIG. 1 will be
mentioned as the upper side and lower side in the vertical
direction, respectively.
[0019] A droplet discharge apparatus 200 illustrated in FIG. 1 is,
for example, an ink jet color printer that uses pigment ink as ink
Q. The droplet discharge apparatus 200 includes: an ink discharge
head 201 for discharging ink Q; a capping unit 202 for preventing
clogging of nozzles 201a of the ink discharge head 201; a tube 203
for coupling the capping unit 202 to a liquid absorbing device 100;
a roller pump 204 for sending ink Q from the capping unit 202 to
the liquid absorbing device 100; and a collecting unit 205.
[0020] In addition, the droplet discharge apparatus 200 also
includes: a control unit 206 for controlling operation at each
section; and a notifying unit 207 for issuing notices, warnings,
and the like based on signals from the control unit 206.
[0021] The ink discharge head 201 has a plurality of nozzles 201a
that discharge ink Q downward. The ink discharge head 201 can
perform printing by discharging ink Q while moving relative to
recording media, such as paper.
[0022] The capping unit 202 prevents clogging of the nozzles 201a
by collectively sucking ink in the respective nozzles 201a through
the operation of the roller pump 204 when the ink discharge head
201 is placed at the standby position.
[0023] The tube 203 is a tubular channel for guiding ink Q sucked
through the capping unit 202 to the liquid absorbing device 100.
The tube 203 is flexible.
[0024] The roller pump 204 is arranged in the intermediate portion
of the tube 203 and includes a roller section 204a and a nip
portion 204b for pinching the intermediate portion of the tube 203
with the roller section 204a. Sucking force is generated at the
capping unit 202 through the tube 203 by rotating the roller
section 204a. Moreover, by continuing the rotation of the roller
section 204a, ink Q attached to the nozzles 201a can be sent out to
the collecting unit 205.
[0025] The collecting unit 205 collects ink Q sent out by the
roller pump 204. In the present embodiment, the liquid absorbing
device 100 is used as the collecting unit 205. Ink Q is absorbed as
waste ink by the liquid absorbing device 100.
[0026] The liquid absorbing device 100 includes: a liquid absorber
10 containing fibers 20 illustrated in FIG. 3 or 4 and an anionic
absorbent resin 30 that is illustrated in FIG. 3 or 4 and that can
absorb ink Q as an exemplary liquid; and a container 9 illustrated
in FIGS. 1 and 2 for storing the liquid absorber 10. The container
9 includes: a feed port 91 to which ink Q is supplied; a storage
section 92 that is connected with the feed port 91 and that stores
the liquid absorber 10; an inflow section 93 into which part of ink
Q can flow when ink Q is supplied to the storage section 92; and a
communicating portion 94 that connects the storage section 92 with
the inflow section 93. Moreover, the liquid absorbing device 100
further includes a detection unit 7 that is provided in the inflow
section 93 and that can detect the liquid surface of ink Q in the
inflow section 93.
[0027] The liquid absorber 10 includes the anionic absorbent resin
30 illustrated in FIG. 3 or 4. The anionic absorbent resin 30 is a
resin that generates anionic groups through dissociation of
hydrophilic groups upon absorption of moisture in a liquid. In this
anionic absorbent resin 30, polymer long chains closely intertwine
with each other under dry conditions but start to spread upon
absorption of moisture in the liquid such that the hydrophilic
groups are dissolved in water. Consequently, it is possible to
absorb much liquid.
[0028] Meanwhile, the anionic absorbent resin 30 exhibits different
absorption characteristics depending on whether a solute contained
in a liquid is an electrolyte or a nonelectrolyte. For example,
when a solute contained in a liquid is a nonelectrolyte, the amount
of absorbed liquid is relatively large regardless of the
concentration of the nonelectrolyte. Accordingly, the anionic
absorbent resin 30 exhibits good absorption characteristics to a
liquid containing a nonelectrolyte regardless of the concentration
of the nonelectrolyte. For this reason, the liquid absorbing device
100 can collect and store a sufficient amount of ink Q. As a
result, it is possible to collect and store regularly generated
waste ink over a long period of time and thus operate a droplet
discharge apparatus 200 in a stable manner.
[0029] In contrast, when a liquid contains an electrolyte, the
anionic absorbent resin 30 tends to decrease the amount of absorbed
liquid as the concentration of the electrolyte increases.
Accordingly, the anionic absorbent resin 30 cannot absorb a
sufficient amount of a liquid containing an electrolyte.
[0030] As described above, the anionic absorbent resin 30 is a
resin that exhibits different absorption characteristics when
liquids to be absorbed have different electrolyte concentrations.
Here, exemplary liquids containing nonelectrolytes as solutes
include pigment ink, whereas exemplary liquids containing
electrolytes as solutes include dye ink.
[0031] By taking account of such absorption characteristics of the
anionic absorbent resin 30, the liquid absorbing device 100
according to the present embodiment includes, as in the foregoing,
the container 9 having: the storage section 92 in which the liquid
absorber 10 containing the anionic absorbent resin 30 is stored;
and the inflow section 93 connected with the storage section 92
into which part of ink Q that has not been absorbed in the storage
section 92 can flow. In the liquid absorbing device 100 illustrated
in FIGS. 1 and 2, the majority of the space in the storage section
92 is filled with the liquid absorber 10 whereas the inflow section
93 is hollow. These storage section 92 and inflow section 93 are
connected through the communicating portion 94.
[0032] When ink Q is supplied from the feed port 91 that is
connected with the storage section 92, ink Q first comes into
contact with the liquid absorber 10 stored in the storage section
92. The droplet discharge apparatus 200 according to the present
embodiment presumes the use of pigment ink. Accordingly, when ink Q
is pigment ink, ink Q is absorbed well by the liquid absorber 10.
As a result, the liquid absorbing device 100 functions well as the
collecting unit 205.
[0033] Moreover, since pigment ink is absorbed by the liquid
absorber 10, the pigment ink does not flow into the inflow section
93. However, when a large amount of pigment ink is supplied, some
of the ink also flows into the inflow section 93 in some cases.
Even in such a case, since the ink is absorbed by the liquid
absorber 10 over time, the liquid surface of the pigment ink in the
inflow section 93 rapidly goes down. Further, it may be designed to
measure the amount of ink Q discharged from the ink discharge head
201 of the droplet discharge apparatus 200 and terminate the
discharge of ink Q before the liquid absorber 10 reaches the
absorption limit.
[0034] Here, a function of monitoring the liquid surface of ink Q
is imparted to the inflow section 93. Specifically, as described
above, the inflow section 93 is provided with the detection unit 7
that can detect the liquid surface of ink Q in the inflow section
93. When pigment ink is used as ink Q, the liquid surface rarely
rises to the height at which the detection unit 7 is provided since
the amount of the pigment ink that flows into the inflow section 93
is small. Consequently, the frequency and time when the detection
unit 7 detects the liquid surface of ink Q are zero or extremely
limited. Based on such detection results of the liquid surface by
the detection unit 7, it is possible to detect that pigment ink is
used as ink Q.
[0035] Now, a case in which dye ink is used as ink Q will be
described. Dye ink is an ink that is not presumed to be used in the
droplet discharge apparatus 200. When dye ink is mistakenly used,
there is a risk of impairing output image quality or causing
clogging of the ink discharge head 201. For this reason, if dye ink
is used, it is required to detect such use rapidly and take
measures therefor.
[0036] When dye ink is used as ink Q, too, the dye ink first comes
into contact with the liquid absorber 10 stored in the storage
section 92. As described above, however, the anionic absorbent
resin 30 included in the liquid absorber 10 lacks satisfactory
absorption characteristics for dye ink, which is an electrolyte
solution. Consequently, the dye ink permeates into the liquid
absorber 10 but accumulates at the bottom of the storage section 92
due to the small absorbed amount. Subsequently, when the liquid
surface of the dye ink reaches the height of the communicating
portion 94, the dye ink flows into the inflow section 93 through
the communicating portion 94. The liquid surface of the dye ink
that has flown into the inflow section 93 gradually rises
corresponding to the amount of the dye ink supplied to the storage
section 92 from the feed port 91. Finally, when the height of the
liquid surface of the dye ink in the inflow section 93 reaches the
detection unit 7, the presence of the liquid surface is detected by
the detection unit 7. In this case, the frequency and/or time when
the detection unit 7 detects the liquid surface increase relative
to a case in which pigment ink is used. In other words, since dye
ink is less likely to be absorbed by the liquid absorber 10, the
liquid surface remains high and is thus kept at the height of the
detection unit 7 more frequently or for a long time after the dye
ink flows into the inflow section 93. For this reason, based on
such detection results, it is possible to detect that dye ink is
used. On such an occasion, as described hereinafter, the droplet
discharge apparatus 200 may cause the notifying unit 207 to issue a
warning about the use of dye ink or cause the control unit 206 to
terminate the discharge of dye ink at the ink discharge head 201.
Consequently, it is possible to prevent damage to the droplet
discharge apparatus 200 or the overflow of dye ink from the liquid
absorbing device 100.
[0037] Even when pigment ink is used, the frequency and/or time
when the detection unit 7 detects the liquid surface may increase
in a similar manner to the foregoing. In such a case, a fact that
the liquid absorber 10 cannot absorb pigment ink satisfactorily is
indirectly detected. In other words, functional failure of the
liquid absorber 10 is suspected since a large amount of pigment ink
flows into the inflow section 93 despite the use of pigment ink. In
this case, too, the droplet discharge apparatus 200 may control the
operation at the ink discharge head 201 to terminate the discharge
of pigment ink. Consequently, the overflow of pigment ink from the
liquid absorbing device 100 can be prevented.
[0038] As in the foregoing, according to the liquid absorbing
device 100 of the present embodiment, it is possible to absorb
pigment ink as an exemplary liquid and, at the same time, easily
detect what type of ink is used for liquids with different
electrolyte concentrations, specifically pigment ink and dye ink,
for example.
[0039] The liquid absorbing device 100 is detachably fitted to the
droplet discharge apparatus 200 and is used in the fitted state for
absorbing ink Q as described above. Accordingly, when the liquid
absorber 10 is determined to have reached the absorption limit
according to the amount of ink Q discharged from the ink discharge
head 201, the liquid absorber 10 may be replaced with a new liquid
absorber 10. When the liquid absorber 10 is determined to have
reached the absorption limit, replacement of the liquid absorber 10
may be recommended by notification through the notifying unit 207
or the like.
[0040] The liquid absorber 10 contains the fibers 20 and the
anionic absorbent resin 30, as described above. When ink Q is
supplied to the liquid absorber 10, the fibers 20 act to retain ink
Q temporarily and then send it to the anionic absorbent resin 30.
Since the fibers 20 act as a buffer through this procedure, it is
possible to enhance absorption characteristics of ink Q by the
liquid absorber 10 as a whole.
[0041] Examples of the fibers 20 include synthetic resin fibers,
such as polyester fibers and polyamide fibers; natural resin
fibers, such as cellulose fibers, keratin fibers, and fibroin
fibers; and chemically modified fibers thereof. These fibers may be
used alone or as an appropriate blend, and are preferably and
primarily cellulose fibers and more preferably almost entirely
cellulose fibers.
[0042] Cellulose is a material with suitable hydrophilicity.
Accordingly, when ink Q is applied to the liquid absorber 10,
cellulose can suitably take up ink Q, thereby swiftly avoiding a
state of particularly high flowability, for example, a state of a
viscosity of 10 mPas or lower, and suitably send ink Q that has
been temporarily taken up to the anionic absorbent resin 30. As a
result, the liquid absorber 10 as a whole can achieve particularly
excellent liquid absorption characteristics. In addition, cellulose
typically has high affinity for the anionic absorbent resin 30 and
thus can further suitably support the anionic absorbent resin 30 on
the surface of the fibers 20. Moreover, cellulose fibers are
renewable natural materials and readily available at low costs
among various fibers. For example, cellulose fibers derived from
waste paper are relatively inexpensive and contribute to a reduced
environmental load. Accordingly, cellulose fibers are also
advantageous in view of the reduced production cost, stable
production, reduced environmental load, and so forth of the liquid
absorber 10.
[0043] Cellulose fibers herein mean any fibrous material
containing, as a main component, cellulose as a compound, in other
words, cellulose in a narrow sense. The cellulose fibers may
contain hemicellulose and/or lignin, in addition to cellulose.
Moreover, the fibers 20 may be bonded with each other by using a
binder, which is not shown.
[0044] The average length of the fibers 20 is not particularly
limited, but is preferably 0.1 mm or more and 7.0 mm or less, more
preferably 0.1 mm or more and 5.0 mm or less, and further
preferably 0.2 mm or more and 3.0 mm or less. The average diameter
of the fibers 20 is not particularly limited, but is preferably
0.05 mm or more and 2.00 mm or less and more preferably 0.10 mm or
more and 1.00 mm or less.
[0045] The average aspect ratio of the fibers 20, in other words, a
ratio of the average length to the average diameter, is not
particularly limited, but is preferably 10 or more and 1,000 or
less and more preferably 15 or more and 500 or less.
[0046] According to the above-mentioned numerical ranges, it is
possible to further suitably support the anionic absorbent resin
30, retain a liquid with the fibers, and/or send out a liquid to
the anionic absorbent resin 30. Consequently, small pieces as a
whole can achieve further excellent liquid absorption
characteristics.
[0047] Here, the average length and average diameter of the fibers
20 are the average values of the lengths and diameters for 100 or
more of the fibers 20, respectively.
[0048] The anionic absorbent resin 30 is not particularly limited
and may be any resin having anionic groups upon absorption of
water. Examples include carboxymethyl cellulose, polyacrylic acid,
polyacrylamide, starch-acrylic acid graft copolymer, hydrolyzed
starch-acrylonitrile graft copolymer, vinyl acetate-acrylic ester
copolymers, isobutylene-maleic acid copolymer, hydrolyzed
acrylonitrile copolymers and acrylamide copolymers, polyethylene
oxide, polysulfonic acid compounds, polyglutamic acid, salts or
neutralized products thereof, and crosslinked products thereof.
Absorbency herein refers to a function of retaining moisture due to
hydrophilicity. Many anionic absorbent resins 30 undergo gelation
upon absorption of water.
[0049] Among these resins, the anionic absorbent resin 30 is
preferably a resin having hydrophilic groups in the side chains.
Exemplary hydrophilic groups include acid groups, such as carboxyl
groups, sulfonic acid groups, phosphate groups, and phosphonic acid
groups.
[0050] In particular, the anionic absorbent resin 30 is preferably
a resin having carboxyl groups in the side chains.
[0051] Exemplary carboxyl group-containing units that constitute
the anionic absorbent resin 30 include those derived from monomers,
such as acrylic acid, methacrylic acid, itaconic acid, maleic acid,
crotonic acid, fumaric acid, sorbic acid, cinnamic acid, anhydrides
thereof, and salts thereof.
[0052] When the anionic absorbent resin 30 having acid groups in
the side chains is used, a proportion of the acid groups in the
anionic absorbent resin 30 that are neutralized to form salts is
preferably 30 mol % or more and 100 mol % or less, more preferably
50 mol % or more and 95 mol % or less, further preferably 60 mol %
or more and 90 mol % or less, and the most preferably 70 mol % or
more and 80 mol % or less. According to such proportions, further
excellent absorption properties of ink Q can be achieved by the
anionic absorbent resin 30.
[0053] The types of neutralized salts are not particularly limited,
and examples include alkali metal salts, such as sodium salts,
potassium salts, and lithium salts; and salts of
nitrogen-containing bases, such as ammonia. Among these salts,
sodium salts are preferable. According to these neutralized salts,
further excellent absorption properties of ink Q can be achieved by
the anionic absorbent resin 30.
[0054] The anionic absorbent resin 30 having acid groups in the
side chains is preferable since the absorption rate becomes fast
due to electrostatic repulsion that arises between the acid groups
during absorption of ink Q. Moreover, when the acid groups are
neutralized, ink Q is readily absorbed inside the anionic absorbent
resin 30 due to osmotic pressure.
[0055] The anionic absorbent resin 30 may have acid group-free
constituent units, and exemplary acid group-free constituent units
include hydrophilic constituent units, hydrophobic constituent
units, and constituent units as polymerizable crosslinkers.
[0056] Examples of the hydrophilic constituent units include
constituent units derived from nonionic compounds, such as
acrylamide, methacrylamide, N-ethyl(meth)acrylamide,
N-n-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide,
N,N-dimethyl(meth)acrylamide, 2-hydroxyethyl (meth)acrylate,
2-hydroxypropyl (meth)acrylate, polyethylene glycol monomethyl
ether (meth)acrylate, polyethylene glycol mono(meth)acrylate,
N-vinylpyrrolidone, N-acryloylpiperidine, and
N-acryloylpyrrolidine. Herein, (meth)acrylic means acrylic or
methacrylic, and a (meth)acrylate means an acrylate or a
methacrylate.
[0057] Examples of the hydrophobic constituent units include
constituent units derived from compounds, such as
(meth)acrylonitrile, styrene, vinyl chloride, butadiene, isobutene,
ethylene, propylene, stearyl (meth)acrylate, and lauryl
(meth)acrylate.
[0058] Examples of the constituent units as the polymerizable
crosslinkers include constituent units derived from diethylene
glycol diacrylate, N,N'-methylenebisacrylamide, polyethylene glycol
diacrylate, polypropylene glycol diacrylate, trimethylolpropane
diallyl ether, trimethylolpropane triacrylate, allyl glycidyl
ether, pentaerythritol triallyl ether, pentaerythritol diacrylate
monostearate, bisphenol diacrylates, diacryloylisocyanurate,
tetraallyloxyethane, and diallyloxyacetate salts.
[0059] The anionic absorbent resin 30 preferably contains an
acrylate salt copolymer or polymerizable crosslinker-crosslinked
polyacrylic acid. As a result, there are advantages, such as
enhanced absorption properties of ink Q and reduced production
costs.
[0060] The polymerizable crosslinker-crosslinked polyacrylic acid
has a proportion of constituent units having carboxyl groups of
preferably 50 mol % or more, more preferably 80 mol % or more, and
further preferably 90 mol % or more based on the total constituent
units that constitute the molecular chain. When a proportion of the
constituent units having carboxyl groups is excessively small, it
may be difficult to achieve satisfactorily excellent absorption
performance of ink Q.
[0061] The carboxyl groups of the polymerizable
crosslinker-crosslinked polyacrylic acid are preferably partially
neutralized, in other words, form salts through partial
neutralization. A proportion of neutralized carboxyl groups in all
the carboxyl groups of the polymerizable crosslinker-crosslinked
polyacrylic acid is preferably 30 mol % or more and 99 mol % or
less, more preferably 50 mol % or more and 99 mol % or less, and
further preferably 70 mol % or more and 99 mol % or less.
[0062] Moreover, the anionic absorbent resin 30 may have a
structure crosslinked with a crosslinker other than the
above-described polymerizable crosslinkers.
[0063] When the anionic absorbent resin 30 is a resin having acid
groups, a compound having a plurality of functional groups that
react with acid groups, for example, is preferably used as such a
crosslinker.
[0064] When the anionic absorbent resin 30 is a resin having
functional groups that react with acid groups, a compound having a
plurality of acid groups within the molecule may be suitably used
as such a crosslinker.
[0065] Examples of the compound having a plurality of functional
groups that react with acid groups include glycidyl ether
compounds, such as ethylene glycol diglycidyl ether,
trimethylolpropane triglycidyl ether, (poly)glycerol polyglycidyl
ether, diglycerol polyglycidyl ether, and propylene glycol
diglycidyl ether; polyhydric alcohols, such as (poly)glycerol,
(poly)ethylene glycol, propylene glycol, 1,3-propanediol,
polyoxyethylene, triethylene glycol, tetraethylene glycol,
diethanolamine, and triethanolamine; and polyamines, such as
ethylenediamine, diethylenediamine, polyethylenimine, and
hexamethylenediamine. In addition, polyvalent ions, such as zinc,
calcium, magnesium, and aluminum, may also suitably be used since
these polyvalent ions act as crosslinkers through reactions with
the acid groups of the anionic absorbent resin 30.
[0066] The anionic absorbent resin 30 may have any shape, such as
flake, needle, fibrous, or granular, and is preferably granular.
When the anionic absorbent resin 30 is granular, permeability of
ink Q can be easily ensured. In addition, the anionic absorbent
resin 30 can be suitably supported on the fibers 20. The average
particle size of such particles is preferably 10 .mu.m or more and
800 .mu.m or less, more preferably 20 .mu.m or more and 600 .mu.m
or less, and further preferably 25 .mu.m or more and 500 .mu.m or
less.
[0067] Further, the liquid absorber 10 may contain components other
than the above-described components. Examples of such components
include surfactants; lubricants; antifoaming agents; fillers;
antiblocking agents; UV absorbers; colorants, such as pigments and
dyes; fireproofing agents; and flow improvers.
[0068] The form of the liquid absorber 10 is not particularly
limited provided that the above-described fibers 20 and anionic
absorbent resin 30 are contained, and exemplary forms include small
pieces, sheets, and fluff. In addition, the form may be a so-called
sandwich form in which the anionic absorbent resin 30 is sandwiched
between sheet fiber substrates containing the fibers 20.
[0069] Among these forms, the liquid absorber 10 is particularly
preferably a small piece aggregate composed of a plurality of small
pieces 1 which are each formed by impregnating a fiber substrate
containing the fibers 20 with the anionic absorbent resin 30, as
illustrated in FIG. 3. A sheet pulverized by a shredder is an
exemplary small piece aggregate. FIG. 3 illustrates two small
pieces 1 included in the liquid absorber 10, as an example. A
plurality of small pieces 1 contained in the small piece aggregate
may have the same configuration as illustrated in FIG. 3 or may
have different configurations.
[0070] Each of the small pieces 1 illustrated in FIG. 3 is a plate
material having two principal surfaces mutually in the front and
rear relationship. The small piece 1 is obtained as a cut piece
(coarsely crushed piece) by impregnating a fiber substrate of
bonded fibers 20 with the anionic absorbent resin 30, followed by
cutting (coarse crushing) into small pieces, as necessary. The
liquid absorber 10, which is an aggregate of such small pieces 1,
can change the shape freely. Accordingly, it is possible to easily
store a desirable amount of the liquid absorber 10 in the storage
section 92 and at the same time, to easily adjust the bulk density,
for example. As a result, it is possible to prevent unevenness in
absorption characteristics of ink Q from arising in the liquid
absorber 10.
[0071] When the small piece 1 is in the above-mentioned sandwich
form as well, the small piece 1 is preferably a plate form having
two principal surfaces mutually in the front and rear relationship.
In such a case, the number of stacked layers of sheet fiber
substrates is not particularly limited as long as two layers or
more. The two principal surfaces mutually in the front and rear
relationship herein refer to the respective surfaces exposed to the
outer space of the small piece 1, for example, the front surface
(first principal surface) and the rear surface (second principal
surface), which is the principal surface on the opposite side, of
the small piece 1 illustrated in FIG. 3.
[0072] The long axis length of the small piece 1, in other words,
the maximum length on the principal surfaces is appropriately set
corresponding to the shape, size, and the like of the container 9
and is preferably 0.5 mm or more and 500 mm or less, more
preferably 1 mm or more and 100 mm or less, and further preferably
2 mm or more and 30 mm or less, for example.
[0073] Moreover, the short axis length of the small piece 1, in
other words, the maximum length in the direction orthogonal to the
long axis on the principal surfaces is appropriately set
corresponding to the shape, size, and the like of the container 9
and is preferably 0.1 mm or more and 100 mm or less, more
preferably 0.3 mm or more and 50 mm or less, and further preferably
1 mm or more and 20 mm or less, for example.
[0074] Further, the aspect ratio of the long axis and short axis of
the small piece 1, in other words, the ratio of the long axis
length to the short axis length is preferably 1.0 or more and 200
or less and more preferably 1.0 or more and 30 or less.
[0075] Still further, the thickness of the small piece 1 is not
particularly limited but is preferably 0.05 mm or more and 2 mm or
less and more preferably 0.1 mm or more and 1 mm or less, for
example.
[0076] Meanwhile, the small pieces 1 preferably satisfy the
following three requirements A, B, and C;
[0077] A: when the liquid is a low-concentration liquid having an
electrolyte concentration of less than 1% by mass at 25.degree. C.,
a ratio of the mass [g] of the low-concentration liquid absorbed
into the anionic absorbent resin 30 to the mass [g] of the anionic
absorbent resin 30 is 20 or more and 600 or less,
[0078] B: when the liquid is a high-concentration liquid having an
electrolyte concentration of 1% by mass or more at 25.degree. C., a
ratio of the mass [g] of the high-concentration liquid absorbed
into the anionic absorbent resin 30 to the mass [g] of the anionic
absorbent resin 30 is 10 or more and less than 20, and
[0079] C: each of the small pieces 1 satisfies relationships of
a.sup.1/2/b>5 and 0.01.ltoreq.b.ltoreq.10.00 where a is the area
[mm.sup.2] of one of the two principal surfaces and b is the
thickness [mm] in a direction normal to the principal surfaces.
[0080] The small pieces 1 that satisfy such three requirements A,
B, and C have elongated principal surfaces, and the anionic
absorbent resin 30 is a resin that exhibits high absorption
characteristics for low-concentration liquids having low
electrolyte concentrations whereas low absorption characteristics
for high-concentration liquids having high electrolyte
concentrations. Accordingly, such small pieces 1 can enhance
absorption efficiency of ink Q by successively absorbing with the
fibers 20 and the anionic absorbent resin 30 while exploiting the
shape as well as allow dye ink to swiftly flow into the inflow
section 93 by utilizing clear differences in absorption
characteristics between low-concentration liquids and
high-concentration liquids. As a result, even when dye ink, in
other words, an unintended type of ink Q is used, such use can be
quickly detected by the detection unit 7 of the liquid absorbing
device 100. Here, the low-concentration liquids are understood as
standard liquids having low electrolyte concentrations, such as
pigment ink whereas the high-concentration liquids are understood
as standard liquids having high electrolyte concentrations, such as
dye ink.
[0081] The ratio in requirement A is preferably 30 or more and 550
or less and more preferably 50 or more and 500 or less.
[0082] The relationships in requirement C are preferably
a.sup.1/2/b>7 and 0.05.ltoreq.b.ltoreq.8.00.
[0083] In the above explanation, an embodiment in which the liquid
absorber 10 includes the anionic absorbent resin 30 is described.
However, such absorbent resins are not limited to anionic absorbent
resins provided that different absorption characteristics are
exhibited depending on whether a solute contained in a liquid is an
electrolyte or a nonelectrolyte. For example, other absorbent
resins may also be used in place of the anionic absorbent resin 30.
However, an anionic absorbent resin is preferably used in view of
the availability, cost, or the like or in view of the large
difference in absorption characteristics.
[0084] The above-described small piece aggregate is a liquid
absorbing material according to the embodiment. In other words, a
liquid absorbing material according to the embodiment is a small
piece aggregate composed of a plurality of small pieces 1 which are
each formed by impregnating a fiber substrate containing the fibers
20 with the anionic absorbent resin 30. This small piece aggregate
exhibits different absorption characteristics depending on
electrolyte concentrations of liquids to be absorbed.
[0085] By using such a liquid absorbing material, for example, as
the liquid absorber 10 of the liquid absorbing device 100, it is
possible to cause liquids having different electrolyte
concentrations to behave differently in response to differences in
absorption characteristics. Consequently, the liquid absorbing
device 100 that can detect a type of ink is easily and successfully
realized by utilizing such behavioral differences.
[0086] Further, as in the foregoing, each of the small pieces 1
contained in the small piece aggregate has at least a first
principal surface and a second principal surface facing a side
opposite to the first principal surface and is in a plate shape
having the principal surfaces exposed outside.
[0087] Since such a liquid absorbing material being a small piece
aggregate can change the shape freely, it is possible, for example,
to easily store a desirable amount of the liquid absorber 10
(liquid absorbing material) in the above-described storage section
92 and to easily adjust the bulk density. As a result, it is
possible to prevent unevenness in absorption characteristics of ink
Q from arising in the liquid absorber 10.
[0088] Next, the container 9 will be described. The container 9
includes the feed port 91, the storage section 92, the inflow
section 93, and the communicating portion 94 as illustrated in
FIGS. 1 and 2. In addition, the container 9 has a lid 8 detachably
fitted to the upper opening 97.
[0089] The container 9 is a box having a bottom 901 and four side
walls 902 standing on the bottom 901. The space surrounded by the
bottom 901 and the four side walls 902 is divided into two portions
of the storage section 92 and the inflow section 93 by an inner
wall 903. The lid 8 has a through hole provided in the thickness
direction, and this through hole constitutes the feed port 91 for
supplying ink Q. The feed port 91 is provided at a position
corresponding to the storage section 92.
[0090] The container 9 may have any shape when viewed from the
perpendicular direction. Exemplary shapes include quadrilateral;
polygons, such as hexagon; circular shapes, such as circle,
ellipse, and oval; and irregular shapes.
[0091] The inner wall 903 has a through hole provided in the lower
portion, and the through hole constitutes the communicating portion
94. In other words, the communicating portion 94 is provided
between a lower portion in the vertical direction of the storage
section 92 and a lower portion in the vertical direction of the
inflow section 93. Through the communicating portion 94, the
storage section 92 and the inflow section 93 are connected.
[0092] By providing the communicating portion 94 at such a
position, excessive ink Q that has not been absorbed into the
liquid absorber 10 in the storage section 92 can be guided to the
communicating portion 94 in a shorter time and is allowed to flow
further into the inflow section 93. Consequently, it is possible to
promptly detect, at the detection unit 7 described hereinafter,
whether ink Q is pigment ink or dye ink.
[0093] The lower portion in the vertical direction of the storage
section 92 herein refers to a 20% or less portion from the lower
end of the full length in the vertical direction of the storage
section 92. In the same manner, the lower portion in the vertical
direction of the inflow section 93 refers to a 20% or less portion
from the lower end of the full length in the vertical direction of
the inflow section 93. The communicating portion 94 may also be
provided in an upper portion in addition to the lower portion of
the inner wall 903.
[0094] The cross-sectional shape of the communicating portion 94,
in other words, the cross-sectional shape when cut in a plane
perpendicular to the thickness direction of the inner wall 903, is
not particularly limited and may be circular, quadrilateral, or
other shapes. However, from a viewpoint of preventing passing of
the small pieces 1 of the liquid absorber 10 stored in the storage
section 92 through the communicating portion 94, a circular shape
is preferable. The communicating portion 94 may be constructed as a
collection of fine through holes, such as a mesh structure or a
slit structure.
[0095] The longest inner diameter on the cross-section of the
communicating portion 94 is not particularly limited but is
preferably 0.1 mm or more and less than the length of the shortest
side on the principal surfaces of the small pieces 1. By setting
the inner diameter of the communicating portion 94 as above, it is
possible to satisfactorily lower the flow resistance in the
communicating portion 94 while preventing the small pieces 1
included in the liquid absorber 10 from unintentionally entering
the communicating portion 94. Consequently, it is possible to keep
the inside of the inflow section 93 hollow without allowing entry
of the small pieces 1 as well as to perform further accurate
detection of a liquid surface at the detection unit 7.
[0096] The volume of the inflow section 93 is preferably smaller
than the volume of the storage section 92. Specifically, a
proportion of the volume of the inflow section 93 to the volume of
the storage section 92 is preferably 0.01% or more and 10.0% or
less and more preferably 0.05% or more and 8.0% or less. According
to such proportions, it is possible to ensure a sufficiently large
volume of the liquid absorber 10 to be stored in the storage
section 92 as well as to increase a displacement range of the
liquid surface of ink Q that has flown into the inflow section 93.
Consequently, it is possible to realize the liquid absorbing device
100 that exhibits an increased amount of ink Q to be absorbed and
excellent detection accuracy in displacement of a liquid surface at
the detection unit 7.
[0097] The liquid absorber 10 is stored in the storage section 92
as described above. When the volume of the storage section 92 is
denoted by V1 and the apparent volume of the liquid absorber 10
before absorbing ink Q is denoted by V2, a ratio of V2 to V1
(V2/V1) is preferably 0.1 or more and 0.7 or less and more
preferably 0.2 or more and 0.7 or less. By setting as above, a void
96 is formed above the liquid absorber 10 within the storage
section 92. After absorbing ink Q, the liquid absorber 10
temporarily swells. On this occasion, ink Q can be retained in this
void 96 temporarily. For this reason, the void 96 acts as a buffer
when the liquid absorber 10 absorbs ink Q. As a result, the liquid
absorber 10 can sufficiently absorb ink Q.
[0098] The container 9 according to the present embodiment is hard,
in other words, does not change 10% or more of the volume even when
internal pressure or external force is exerted on the container 9.
Accordingly, deformation can be suppressed even when internal
pressure or external force is exerted on the container 9. As a
result, the installation state of the container 9 stabilizes within
the droplet discharge apparatus 200, and the liquid absorber 10 can
absorb ink Q in a stable manner.
[0099] Component materials for the container 9 are not particularly
limited unless the component materials allow permeation of ink Q.
Exemplary component materials for the container 9 include various
resin materials, such as cyclic polyolefins and polycarbonates.
Moreover, other than the above-mentioned various resin materials,
various metal materials, such as aluminum and stainless steel, can
also be used as the component materials for the container 9.
[0100] The container 9 is not limited to a hard one and may also be
flexible, in other words, may change 10% or more of the volume when
internal pressure or external force is exerted on the container
9.
[0101] Moreover, the container 9 may be either transparent with
visibility of the inside or opaque, but at least part of the
container 9 and the lid 8 described hereinafter preferably has
visibility of the inside.
[0102] Meanwhile, the lid 8 has a plate shape and is fitted into
the upper opening 97 of the container 9 as illustrated in FIGS. 1
and 2. By such fitting, even when ink Q is discharged from the tube
203, dropped, and splashed on the liquid absorber 10, outward
scattering of ink Q can be prevented. Accordingly, it is possible
to prevent soiling through attachment of ink Q to the surroundings
of the liquid absorbing device 100.
[0103] Even when the lid 8 is provided, ventilation of the storage
section 92 and the inflow section 93 with the outside air is
ensured. Consequently, it is possible to allow ink Q to flow
smoothly from the storage section 92 into the inflow section
93.
[0104] Further, the lid 8 may be provided as necessary and may also
be omitted. In such a case, the upper surface of the container 9 is
exposed and a portion of the upper opening 97 corresponding to the
storage section 92 constitutes the above-described feed port
91.
[0105] The tube 203 is coupled to the feed port 91 that is provided
in the central part of the lid 8. In this configuration, an outlet
203a of the tube 203 faces downward in the vertical direction.
Here, the feed port 91 may be shifted from the central part, and
the outlet 203a of the tube 203 may face a direction other than
downward in the vertical direction.
[0106] The lid 8 may exhibit absorption properties for absorbing
ink Q or exhibit liquid repellency for repelling ink Q.
[0107] The thickness of the lid 8 is not particularly limited and
is preferably 1 mm or more and 20 mm or less and more preferably 8
mm or more and 10 mm or less. Here, the lid 8 is not limited to a
plate shape having the above-mentioned numerical ranges and may be
a thinner film shape. In this case, the thickness of the lid 8 is
not particularly limited and is 10 .mu.m or more and less than 1
mm, for example.
[0108] Moreover, the lid 8 may exhibit water vapor permeability as
necessary. By this property, moisture evaporated from absorbed ink
Q is allowed to permeate outside. Consequently, it is possible to
ensure a larger amount of ink Q to be absorbed by the liquid
absorber 10.
[0109] In this case, the water vapor permeability of the lid 8 is
preferably 1.0 g/m.sup.2day (40.degree. C.90% RH) or more and 5,000
g/m.sup.2day (40.degree. C.90% RH) or less and more preferably 2.0
g/m.sup.2day (40.degree. C.90% RH) or more and 2,000 g/m.sup.2day
(40.degree. C.90% RH) or less. According to these ranges of the
water vapor permeability, the above-mentioned effects can be
exerted reliably.
[0110] Component materials for above-described container 9 and lid
8 are not particularly limited, and various resin materials, for
example, may suitably be used. Exemplary resin materials include
various thermoplastic resins and various curable resins, such as
thermosetting resins and photocurable resins. Specific examples
include polyolefins, such as polyethylene, polypropylene, and
ethylene-propylene copolymer; polyvinyl chloride; polystyrene;
polyamides; polyimides; polycarbonates; poly(4-methylpentene-1);
ionomers; acrylic resins; poly(methyl methacrylate);
acrylonitrile-butadiene-styrene copolymer (ABS resin);
acrylonitrile-styrene copolymer (AS resin); butadiene-styrene
copolymer; polyesters, such as poly(ethylene terephthalate) (PET)
and poly(butylene terephthalate) (PBT); polyethers; polyether
ketones (PEK); polyether ether ketones (PEEK); polyether imides;
polyacetal (POM); polyphenylene oxide; polysulfones; polyether
sulfones; polyphenylene sulfide; polyarylates; aromatic polyesters
(liquid crystal polymers); polytetrafluoroethylene; polyvinylidene
fluoride; other fluororesins; epoxy resins; phenolic resins; urea
resins; melamine resins; silicone resins; polyurethanes; and
copolymers, blends, and polymer alloys primarily containing these
resins. These resins may be used alone or in combination.
[0111] The detection unit 7 is provided in the inflow section 93 of
the container 9. As mentioned above, the detection unit 7 detects
the presence of the liquid surface of ink Q that has flown into the
inflow section 93. The detection method for the liquid surface by
the detection unit 7 is not particularly limited, and examples
include an electrically detecting method, an optically detecting
method, a thermally detecting method, and a mechanically detecting
method.
[0112] Among these methods, the detection unit 7 according to the
present embodiment electrically detects ink Q, which is a liquid,
and thus includes pairs of electrodes 711 and 712, an IC chip 72,
and wiring 73 for electrically coupling the electrodes 711 and 712
to the IC chip 72. Specifically, a current value between the
electrodes 711 and 712 or a resistance value between the electrodes
711 and 712 is measured at the IC chip 72. Since ink Q has higher
electric conductivity than air, the IC chip 72 determines that ink
Q is detected between the electrodes 711 and 712, for example, when
the current value is equal to or more than a predetermined value or
when the resistance value is less than a predetermined value.
Meanwhile, the IC chip 72 determines that ink Q is not detected
between the electrodes 711 and 712 when the current value is less
than a predetermined value or when the resistance value is equal to
or more than a predetermined value. In other words, the IC chip 72
has a function of measuring a current value or a resistance value
and a function of determining whether ink Q is detected or not
based on the measured results.
[0113] The IC chip 72 is electrically coupled to the
above-mentioned control unit 206 of the droplet discharge apparatus
200 through wiring 208. The control unit 206 can presume that ink Q
is dye ink when ink Q is detected at the detection unit 7 and that
ink Q is pigment ink when ink Q is not detected.
[0114] According to the above-described electrical detection
method, the type of ink Q can be detected further easily. In
addition, due to the relatively simple configuration of the
detection unit 7, there is also an advantage that the liquid
absorbing device 100 is readily downsized.
[0115] The electrodes 711 and 712 illustrated in FIGS. 1 and 2 are
each provided inside the inflow section 93. However, the electrodes
711 and 712 may partially constitute the side wall 902 provided
that the electrodes 711 and 712 can come into contact with ink Q.
Moreover, the electrodes 711 and 712 may be provided outside the
side wall 902 and come into contact with ink Q via through holes of
the side wall 902.
[0116] Further, the IC chip 72 illustrated in FIGS. 1 and 2 is
provided outside the side wall 902 but may partially constitute the
side wall 902.
[0117] The IC chip 72 is coupled to the above-mentioned control
unit 206 through the wiring 208. However, between the contact of
the IC chip 72 and the wiring 208 or between one wiring 208 and
another wiring 208, for example, may be freely disconnected. By
this configuration, the detection unit 7 and the control unit 206
can be electrically connected when the container 9 and the
detection unit 7 attached to the container 9 are installed on the
main body side of the droplet discharge apparatus 200. Meanwhile,
the detection unit 7 can be insulated from the control unit 206
when the container 9 and the detection unit 7 are detached from the
main body side of the droplet discharge apparatus 200. As a result,
the liquid absorbing device 100 is exchangeable.
[0118] The IC chip 72 may be provided as necessary and may also be
omitted. In such a case, the electrodes 711 and 712 are provided in
the container 9, and the IC chip 72 may be provided on the main
body side of the droplet discharge apparatus 200. Moreover, the IC
chip 72 may be detached freely from the electrodes 711 and 712.
[0119] As mentioned above, exemplary detection methods for a liquid
surface by the detection unit 7 include methods other than the
electrically detecting method.
[0120] Among these methods, an optically detecting method will be
described hereinafter. Meanwhile, exemplary thermally detecting
methods include a method of detecting the presence or absence of
ink Q by detecting temperature changes, for example. Further,
exemplary mechanically detecting methods include a method that uses
a float and detects the float being pushed up as a liquid surface
rises and a method that uses a pressure gauge and detects an
increase in pressure as a liquid surface rises.
[0121] It is possible to detect the inflow of ink Q into the inflow
section 93 earlier as the position of the detection unit 7 is
closer to the lower side in the inflow section 93. In contrast, it
is possible to delay such detection as the position of the
detection unit 7 is closer to the upper side in the inflow section
93. Accordingly, based on the above view, the position of the
detection unit 7 in the inflow section 93 may be set
appropriately.
[0122] For example, the position of the detection unit 7 in the
inflow section 93 is preferably a 70% or less position, more
preferably a 1% or more and 60% or less position, and further
preferably a 5% or more and 50% or less position from the lower end
in the full length in the vertical direction of the inflow section
93. By setting the position of the detection unit 7 within the
above-mentioned ranges, it is possible to prevent extremely early
detection of the liquid surface of ink Q as well as to detect a
rise in liquid surface of ink Q before ink Q overflows.
Consequently, a rise in liquid surface that arises when dye ink is
used is selectively and readily detected without excessively
detecting a rise in liquid surface that may also arise even when
pigment ink is used. As a result, it is possible to detect, in the
droplet discharge apparatus 200, the use of dye ink at a high
probability while preventing needless issuing of warnings or
termination of operation when pigment ink is used.
[0123] Meanwhile, the rising rate of the liquid surface of ink Q
also varies depending on interactions between ink Q and the liquid
absorber 10. Accordingly, the position of the detection unit 7 may
be determined in advance through experiments or the like. For
example, each of the above-mentioned low-concentration liquid and
high-concentration liquid is supplied from the feed port 91 in an
amount of 30% of the volume of the storage section 92 at a rate of
1 cc/h. The position of the detection unit 7 is determined, at the
end of supplying, within a range higher than the height reached by
the surface of the low-concentration liquid and equal to or lower
than the height reached by the surface of the high-concentration
liquid. As a result, it is possible to detect at a high probability
a rise in liquid surface that arises when dye ink as an exemplary
high-concentration liquid is used without detecting a rise in
liquid surface that may also arise even when pigment ink as an
exemplary low-concentration ink is used.
[0124] Next, a control method for the liquid absorbing device
according to the first embodiment will be described. FIG. 5 is a
flow chart showing the control method for the liquid absorbing
device according to the first embodiment.
[0125] The control method for the liquid absorbing device 100 shown
in FIG. 5 includes: step S1 of acquiring data about frequency or
time when the surface height of ink Q, which is a liquid detected
by the detection unit 7, exceeds a reference value; and step S2 of
determining a type of ink Q based on the data. Hereinafter, each
step will be described.
[0126] First, when ink Q is supplied from the feed port 91, ink Q
flows into the inflow section 93 through the storage section 92 and
the communicating portion 94. The detection unit 7 outputs changes
in current value or resistance value obtained at the electrodes 711
and 712 to the IC chip 72. The IC chip 72 then records frequency or
time when ink Q is detected based on the number of times or
duration when the current value or resistance value changes. In
other words, data about frequency or time when the liquid surface
height of ink Q is considered to exceed a reference value is
acquired. Such data is recorded, for example, as data about
cumulative frequency or cumulative time from the start of using the
liquid absorbing device 100.
[0127] Next, the IC chip 72 determines a type of ink Q based on the
acquired data. Specifically, for example, the acquired data is
compared with a threshold value stored in advance for cumulative
frequency or cumulative time. When the acquired data is equal to or
more than the threshold value, ink Q is determined to be dye ink.
Meanwhile, when the acquired data is less than the threshold value,
ink Q is determined to be pigment ink.
[0128] Here, the threshold value for frequency or time may be
changeable afterwards. Moreover, data to be recorded at the IC chip
72 may be resettable.
[0129] According to the above-described control method for the
liquid absorbing device 100, it is possible to easily detect what
type of ink is used for liquids having different electrolyte
concentrations, specifically pigment ink and dye ink, for
example.
[0130] Subsequently, the determined results may be output to the
control unit 206 of the droplet discharge apparatus 200 or may be
stored at the IC chip 72. FIG. 5 also shows control details at the
control unit 206 of the droplet discharge apparatus 200, in
addition to the control method for the liquid absorbing device 100.
In other words, FIG. 5 shows an example in which determined results
are output to the control unit 206 and also utilized for the
control of the droplet discharge apparatus 200.
[0131] When ink Q is determined to be dye ink, the control unit
206, as necessary, terminates the discharge of dye ink at the ink
discharge head 201 and/or causes the notifying unit 207 to issue a
warning about the use of dye ink. As a result, it is possible to
prevent damage to the droplet discharge apparatus 200 and/or
overflow of dye ink from the liquid absorbing device 100.
[0132] When ink Q is determined to be dye ink, a warning is first
issued as the initial stage as in step S3 shown in FIG. 5. After
that, when data indicating dye ink continue to be acquired even
after the passage of a predetermined time, as the next stage, the
discharge of ink Q at the ink discharge head 201 is terminated as
in step S4 shown in FIG. 5. Through this stepwise procedure, the
droplet discharge apparatus 200 may be controlled.
[0133] Here, the predetermined time may be time stored at the
control unit 206 in advance or time changeable afterwards.
Second Embodiment
[0134] Next, a liquid absorbing device according to the second
embodiment will be described. FIG. 6 is a partial vertical
cross-sectional view illustrating the liquid absorbing device
according to the second embodiment in use.
[0135] Hereinafter, the second embodiment will be described. In the
following explanation, differences from the foregoing embodiment
will be mainly described while omitting the explanation about
similar matters. In FIG. 6, similar components to those in the
foregoing embodiment are denoted by the same signs.
[0136] The second embodiment is the same as the first embodiment
except for the configuration of the detection unit 7. The detection
unit 7 according to the above-described first embodiment includes
the electrodes 711 and 712 and the IC chip 72 whereas the detection
unit 7 according to the present embodiment is provided in the side
wall 902 and includes a window 76 for optically detecting the
liquid surface of ink Q as an exemplary liquid. The window 76 is
translucent and allows the liquid surface of ink Q that has flown
into the inflow section 93 to be viewed from the outside of the
container 9. According to such an optical detection method, the
liquid absorbing device 100 can be easily downsized due to the
relatively simple configuration of the detection unit 7. In
addition, when the liquid surface is optically detected through the
window 76, physical contact between a detection means and the
window 76 is not needed. Accordingly, it is possible to easily
perform detachment operation of the container 9 and the detection
unit 7 attached to the container 9 from the main body side of the
droplet discharge apparatus 200.
[0137] Here, the window 76 also acts as part of the side wall 902
and is provided such that liquid tightness is maintained between
the window 76 and the side wall 902. As a result, leakage of ink Q
from the inflow section 93 is prevented.
[0138] Moreover, the droplet discharge apparatus 200 illustrated in
FIG. 6 includes a photoelectric sensor 209 provided at a position
facing the window 76. The photoelectric sensor 209 optically
detects the presence or absence of ink Q through the window 76 by
irradiating the window 76 and measuring the quantity of reflected
light. Specifically, when the photoelectric sensor 209 irradiates
inside the inflow section 93 through the window 76 and if ink Q is
present in the inflow section 93, light reflected by ink Q reaches
the photoelectric sensor 209 through the window 76 again.
Meanwhile, when ink Q is absent in the inflow section 93, light
reflected by the inner wall of the inflow section 93 reaches the
photoelectric sensor 209. On such an occasion, reflectance on a
reflecting surface varies depending on the component materials
and/or surface state of the reflecting surface. In other words, the
quantity of reflected light varies depending on whether light is
reflected by ink Q or reflected by the inner wall of the inflow
section 93. Accordingly, it is possible to determine the presence
or absence of ink Q by measuring and comparing the quantity of
light received at the photoelectric sensor 209.
[0139] Further, other than the quantity of received light, the
presence or absence of ink Q may be determined according to the
color of a reflecting surface. Since ink Q is waste ink, it often
shows a black color. Accordingly, the photoelectric sensor 209 may
be configured to irradiate with three color light of red, blue, and
green and measure the color of light reflected by ink Q, in other
words, the colorimetric value. By designing the color of the inner
wall of the inflow section 93 as a color other than black, a
difference arises between the colorimetric value of light reflected
by ink Q and the colorimetric value of light reflected by the inner
wall of the inflow section 93. Consequently, it is also possible to
determine the presence or absence of ink Q according to
colorimetric values.
[0140] The photoelectric sensor 209 is electrically coupled to the
control unit 206 as illustrated in FIG. 6. Accordingly, based on
the results detected by the photoelectric sensor 209, the control
unit 206 may be configured to terminate the discharge of dye ink at
the ink discharge head 201 and/or cause the notifying unit 207 to
issue a warning about the use of dye ink, for example.
[0141] In the present embodiment, the photoelectric sensor 209 is
provided on the main body side of the droplet discharge apparatus
200 rather than in the liquid absorbing device 100. However, the
photoelectric sensor 209 may be built in the liquid absorbing
device 100. In such a case, an IC chip may be mounted together with
the photoelectric sensor 209, and the liquid absorbing device 100
may be configured to perform a process of determining a type of ink
Q and output the determined results.
[0142] The photoelectric sensor 209 illustrated in FIG. 6 is a
so-called reflective sensor but may be a transmission sensor
composed of a light transmitter and a light receiver. In this case,
windows 76 may be each provided at two positions of the side wall
902 via the inflow section 93 of the container 9. The light
transmitter may be set facing either of the windows 76 whereas the
light receiver may be set facing the other window 76. By this
configuration, it is possible to detect changes in quantity of
light transmitting the inflow section 93. Consequently, the
presence or absence of ink Q can be detected based on the quantity
of received light or colorimetric values in a similar manner to the
foregoing.
[0143] In place of the photoelectric sensor 209, an imaging sensor,
a photodiode, and so forth may be used as well. In the second
embodiment as described above as well, effects similar to the
effects of the first embodiment can also be obtained.
Third Embodiment
[0144] Next, a liquid absorbing device according to the third
embodiment will be described.
[0145] FIG. 7 is a conceptual diagram illustrating the liquid
absorbing device according to the third embodiment. Here, FIG. 7 is
a diagram for illustrating the concept of the detection unit 7 and
thus does not take account of the positional relationship between
the container 9 and the detection unit 7 for convenience of
explanation.
[0146] Hereinafter, the third embodiment will be described. In the
following explanation, differences from the foregoing embodiments
will be mainly described while omitting the explanation about
similar matters. In FIG. 7, similar components to those in the
foregoing embodiments are denoted by the same signs. The third
embodiment is the same as the first embodiment except for the
configuration of the detection unit 7.
[0147] The detection unit 7 illustrated in FIG. 7 includes an
input/output unit 74, a terminal unit 75, two electric leads 761
and 762 for electrically coupling these units, and an IC chip
72.
[0148] The input/output unit 74 is coupled to each end of the two
electric leads 761 and 762. From the output portion of the
input/output unit 74, a pulse signal is output to the terminal unit
75 through one electric lead 761. When the pulse signal returns
through the other electric lead 762, the signal is input to the
input portion of the input/output unit 74. Moreover, the
input/output unit 74 has a function of measuring the voltage of the
pulse signal input to the input portion and comparing the voltage
with a threshold value stored in advance. Here, the input/output
unit 74 is provided outside the inflow section 93, for example.
[0149] Meanwhile, the terminal unit 75 is coupled to the other end
of the two electric leads 761 and 762. A pulse signal input to one
electric lead 761 attenuates at the terminal unit 75 and is not
output to the other electric lead 762. In other words, the terminal
unit 75 has a function of shielding a pulse signal. Here, the
terminal unit 75 is provided outside the inflow section 93, for
example, but may be provided inside the inflow section 93.
[0150] Both of the two electric leads 761 and 762 are placed, for
example, to penetrate the side wall 902, pass through the inside of
the inflow section 93, and penetrate the side wall 902 again. At
least part of the two electric leads 761 and 762 that are
positioned inside the inflow section 93 lack sheaths and the like.
Accordingly, when ink Q that has flown into the inflow section 93
simultaneously comes into contact with both of the two electric
leads 761 and 762, the electric leads 761 and 762 are designed to
short-circuit. Meanwhile, the electric leads 761 and 762 are set
apart from each other and are designed not to short-circuit when
ink Q does not come into contact with the electric leads
simultaneously.
[0151] In the above-described detection unit 7, when ink Q does not
reach the height of the detection unit 7, in other words, when ink
Q does not come into contact with the two electric leads 761 and
762, the electric leads 761 and 762 do not short-circuit. As a
result, a pulse signal output from the input/output unit 74 is
shielded at the terminal unit 75 and does not return to the
input/output unit 74.
[0152] Meanwhile, when ink Q reaches the height of the detection
unit 7, in other words, when ink Q comes into contact with the two
electric leads 761 and 762, the electric leads 761 and 762
short-circuit. As a result, a pulse signal output from the
input/output unit 74 returns to the input/output unit 74 through
the short-circuited portion due to ink Q.
[0153] Through this procedure, it is possible to detect the
presence of ink Q based on the presence or absence of a pulse
signal that returns to the input/output unit 74 and further, to
presume a type of ink Q. In the above-described third embodiment as
well, effects similar to the effects of the foregoing embodiments
can also be obtained.
[0154] The detection unit 7 illustrated in FIG. 7 may further have
a function of detecting the disconnection of the electric leads 761
and 762. A pulse signal also does not return to the input/output
unit 74 when at least either of the two electric leads 761 and 762
is disconnected. Accordingly, there is a problem in which it is
impossible to determine, solely from the result of a received pulse
signal, whether ink Q is not detected or the disconnection
occurs.
[0155] By imparting a function of detecting the disconnection of
the electric leads 761 and 762 to the detection unit 7 illustrated
in FIG. 7, it is possible to enhance the reliability of the liquid
absorbing device 100. Specifically, the detection unit 7
illustrated in FIG. 7 has a function of regularly setting a period
of time without outputting a pulse signal while outputting a
direct-current signal in this period of time. Meanwhile, the
terminal unit 75 has a function of passing through a direct-current
signal while shielding a pulse signal as described above.
[0156] As a result, when both of the two electric leads 761 and 762
are normal, in other words, when neither of the electric lead 761
or 762 is disconnected, a direct-current signal output from the
input/output unit 74 returns to the input/output unit 74 via the
terminal unit 75.
[0157] Meanwhile, either of the two electric leads 761 and 762 is
disconnected, a direct-current signal output from the input/output
unit 74 is interrupted at the disconnected portion and does not
return to the input/output unit 74.
[0158] As described above, the disconnection of the electric leads
761 and 762 can be detected based on whether a direct-current
signal returns to the input/output unit 74. As a result, it is
possible to enhance the reliability of the liquid absorbing device
100.
[0159] The result of the detected disconnection may also be output
to the control unit 206 of the droplet discharge apparatus 200, as
necessary, or may be stored at the IC chip 72. The control unit
206, as necessary, terminates the discharge of ink Q at the ink
discharge head 201 and/or causes the notifying unit 207 to issue a
warning about the disconnection of the electric leads 761 and
762.
Fourth Embodiment
[0160] Next, a liquid absorbing device according to the fourth
embodiment will be described. FIG. 8 is a partial vertical
cross-sectional view illustrating the liquid absorbing device
according to the fourth embodiment in use.
[0161] Hereinafter, the fourth embodiment will be described. In the
following explanation, differences from the foregoing embodiments
will be mainly described while omitting the explanation about
similar matters. In FIG. 8, similar components to those in the
foregoing embodiments are denoted by the same signs. The fourth
embodiment is the same as the second embodiment except for the
configuration of the container 9.
[0162] The container 9 illustrated in FIG. 8 includes a pipe 95
provided outside the side wall 902 instead of omitting the inner
wall 903. Moreover, the side wall 902 has through holes provided on
both the lower side and the upper side. The through hole on the
lower side constitutes a communicating portion 941 that connects
the storage section 92 with the pipe 95 whereas the through hole on
the upper side constitutes a communicating portion 942 that
connects the storage section 92 with the pipe 95. In other words,
one end of the pipe 95 is coupled to the communicating portion 941
and the other end is coupled to the communicating portion 942.
Accordingly, the inner space of the pipe 95 has the same function
as the above-described inflow section 93.
[0163] Further, the pipe 95 is translucent. Accordingly, the pipe
95 allows the liquid surface of ink Q that has flown into the pipe
95 to be viewed from the outside of the container 9. Consequently,
the pipe 95 as a whole constitutes the above-described window 76.
Here, the pipe 95 may be only partially translucent, and the
remainder need not be translucent. In such a case, the translucent
part constitutes the window 76. In the above-described fourth
embodiment as well, effects similar to the effects of the foregoing
embodiments can also be obtained.
[0164] In the forgoing, the liquid absorbing device, the control
method for the liquid absorbing device, and liquid absorbing
material of the present disclosure are described based on the
embodiments illustrated in the figures. The present disclosure,
however, is not limited to these embodiments. For example,
exemplary liquids having different electrolyte concentrations
include pigment ink and dye ink in the above-described embodiments,
and these embodiments have a function capable of detecting which
ink is supplied. However, such liquids having different electrolyte
concentrations are not limited to these inks and may be other
liquids. Moreover, the configuration of each unit in the liquid
absorbing device may be substituted with any configuration having
the same function. Further, any other component may be added to the
present disclosure. Still further, the embodiments may be
appropriately combined with each other.
* * * * *